Newborn screening programs have dramatically expanded in the past 25 years driven by the availability of new technology and by the improved outcome of patients identified and treated early. Several genetic, metabolic and endocrine, conditions are amenable to detection in the newborn period. Among metabolic disorders, those identified by newborn screening are disturbances in the metabolism of amino acids and fatty acid oxidation that are detected by tandem mass spectrometry (MS/MS). This technology has the advantage of detecting multiple analytes, therefore multiple diseases, simultaneously. One of the disadvantages is that, in order to identify as many affected infants as possible, there can be a fairly large number of false positive results. This can place undue stress on the families and on the public health follow up program. To alleviate this problem, the specificity of the testing can be increased by the use of second tier tests, performed on the same sample used for the primary analysis, targeting different analytes. Unfortunately, not all states have the resources to implement these second tier tests. In addition, efficiency and cost effectiveness increase when a large number of samples are processed (economy of scale). This project will evaluate the effectiveness of regional second tier tests in the Mountain States (Region 6) and the feasibility of a regional center for these activities. We will develop protocols for the processing and testing of blood spots with abnormal results for certain analytes (17-OHP, C3, methionine, tyrosine), appropriate testing algorithms and reporting procedures to significantly reduce the need for follow-up testing. This proposal will test the feasibility of a regional center for newborn screening and result in increased sensitivity and specificity of currently existing newborn screening programs in the mountain state region. PUBLIC HEALTH RELEVANCE: The expansion of newborn screening gives the opportunity to diagnose children with conditions for which early therapy can improve clinical outcome. This project will implement the use of additional (second-tier) tests in newborn screening to make sure that all disorders are properly identified and to reduce the number of children who test positive, but do not have the disease (false positive).